This document discusses melanoma, the most fatal form of skin cancer. It covers the incidence and risk factors of melanoma including genetics, sun exposure, and skin phenotype. The clinical features and subtypes of melanoma like superficial spreading, nodular, lentigo maligna, and acral lentiginous melanoma are described. Diagnosis involves methods like the ABCDE rule and biopsy for suspicious lesions. Staging uses the TNM system and prognostic factors include tumor thickness and mitotic rate. Management involves wide local excision of primary tumors and sentinel lymph node biopsy for involved nodes. Long term surveillance after treatment monitors for recurrence.
2. MELANOMA
• Incidence is increasing
• Lifetime probability of developing melanoma
• 1/37 men
• 1/56 women
• Five-year survival rates depend upon the stage of the
disease at the time of diagnosis
• Rare in children and adolescents
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3. RISK FACTORS
• Genotype
• Personal history of skin cancer
• Family history
• Atypical nevi
• Common nevi
• Phenotype
• Sun exposure
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4. SUN EXPOURE
• Higher rates with extensive or repeated intense exposure
to sunlight
• Greater penetration of UV light into the skin results in a
higher risk
• Incidence is highest in equatorial areas and decreases
proportionately with distance from the equator
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5. • Decrease in recreational sun exposure following the
diagnosis of primary melanoma, can significantly diminish
the chance of a second primary melanoma
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6. • UV-A versus UV-B irradiation
• UV-A 320-400 nm
• UV-B 290-320 nm
• PUVA therapy (Psoralen)
• Late increase in the risk of melanoma
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7. TIMING AND PATTERN OF SUN EXPOSURE
• Nonmelanoma cancers are associated with cumulative
sun exposure
• Melanomas are associated with intense, intermittent sun
exposure and sunburns
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8. • Tanning beds (since 1920)
• Deep tan – status symbol
• WHO (2009) UV-A from tanning beds as human carcinogen
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9. CLINICAL FEATURES
• Superficial tumors that are confined to the epidermis
• Horizontal or "radial" growth phase
• “Vertical" growth phase
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11. SUPERFICIAL SPREADING MELANOMA
• The most common subtype
• Over 60% are diagnosed as thin, highly curable tumors of
less than 1 mm thickness
• Can occur in any anatomic location
• Variably pigmented macule or plaque with an irregular
border, ranging from a few millimeters to several
centimeters in diameter
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12. • Multiple shades of red, tan, brown, blue, black, gray, and
white can be appreciated
• Histologically
• Asymmetric, poorly circumscribed, lack cellular maturation
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13. • In the radial phase of growth, there is haphazard growth
of neoplastic melanocytes with single-cell spread
throughout the layers of the epidermis
• Transition to vertical growth phase occurs when the
largest nest in the dermis exceeds that in the epidermis
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15. NODULAR MELANOMA
• Vertical growth phase melanomas
• 15 to 30 percent of all melanomas
• Darkly pigmented, pedunculated or polypoid nodule
• Histologically
• Dermal growth occurs in isolation or, occasionally
• Neoplastic cells within the dermal growth may appear epithelioid or
spindled
• Mitoses are frequent and often atypical
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17. LENTIGO MALIGNA MELANOMA
• Most commonly arises in sun-damaged areas of the skin in
older individuals
• Begins as a freckle-like tan-brown macule
• Transformation is slow
• Once it is fully evolved, color variegation can be striking
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18. • Histologically
• During the radial growth phase, the atypical melanocytes are usually
polygonal in shape with hyperchromatic, angulated nuclei
• Multinucleated giant melanocytes ("star-burst giant cells") may be
present at the basal layer of the epidermis
• The hallmark of the vertical growth phase is the formation of dermal
nodules and fascicles that are larger than the epidermal component
• Pleomorphic with variably hyperchromatic nuclei
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20. ACRAL LENTIGINOUS MELANOMA
• The least common variant of radial growth phase melanomas
• Fewer than 5 percent of all melanomas
• Palmar, plantar, subungual, and occasionally, mucosal surfaces
• Most common type of malignant melanoma among asians
and dark-skinned individuals
• Not all melanomas arising in acral sites are acral lentiginous
melanomas
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21. • Dark brown to black, unevenly pigmented patch
• Areas of regression manifest as foci of gray-white
discoloration
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22. • Histologically
• Lentiginous array of atypical melanocytes along the dermal-
epidermal junction, with foci of confluent melanocytic growth
• Invasive lesions are characterized by the presence of neoplastic
single cells or nests in the dermis
• Large, hyperchromatic, angulated melanocytes with scant
cytoplasm
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24. DIAGNOSIS
• The clinical recognition of melanoma may be challenging
even for the most experienced dermatologist
• Asymmetry
• Irregular borders
• Variegated color
• Diameter >6mm
• Recent change in a lesion
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25. ABCDE RULE
• Asymmetry (if a lesion is bisected, one half is not identical to
the other half)
• Border irregularities
• Color variegation (brown, red, black or blue/gray, and white)
• Diameter ≥6 mm
• Evolving: a lesion that is changing in size, shape, or color, or a
new lesion
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26. THE REVISED GLASGOW SEVEN-POINT
CHECKLIST
• Major:
• Change in size/new lesion
• Change in shape
• Change in color
• Minor:
• Diameter ≥7mm
• Inflammation
• Crusting or bleeding
• Sensory change
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27. THE "UGLY DUCKLING" SIGN
• A pigmented lesion that looks different from other
surrounding lesions must be considered suspicious, even if
it does not fulfill the ABCD criteria.
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30. MANAGEMENT OF PATIENTS WITH
SUSPICIOUS SKIN LESIONS
• Referral
• Biopsy
• Monitoring
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31. • Referral
• A new mole appearing after the onset of puberty which is changing in shape, color, or
size
• A long-standing mole which is changing in shape, color, or size
• Any mole which has three or more colors or has lost its symmetry
• A mole which is itching or bleeding
• Any new persistent skin lesion especially if growing, if pigmented or vascular in
appearance, and if the diagnosis is not clear
• A new pigmented line in a nail especially where there is associated damage to the nail
• A lesion growing under a nail
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32. • Biopsy
• Biopsy is necessary whenever melanoma is suspected.
• An excisional biopsy that includes the entire lesion with 1 to 3
mm margins of normal skin and part of the subcutaneous fat
should be performed whenever possible.
• Incisional biopsy may be occasionally acceptable for very large
lesions or for certain sites, including the face, palm or sole, ear,
distal digit, or subungual lesions
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33. • Monitoring
• Patients at increased risk of melanoma should have regular
examinations once or twice a year
• Australian Cancer Network recommends monthly skin self-
examination and biannual full body skin examination by a
clinician for high risk individuals
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37. INITIAL BIOPSY
• Excisional biopsy
• Incisional biopsy
• Shave biopsy
• Never appropriate for the following reasons
• The lesion is likely to be inadequately excised, with residual tumor remaining at both the radial and
deep margins.
• Because only the superficial portion of the tumor is removed, shave biopsies results underestimate
tumor thickness, a critical prognostic factor and determinant of treatment.
• Fibrosis and scarring at the base of the biopsy site may obscure residual melanoma, making it
impossible for a pathologist to identify tumor and accurately measure its thickness.
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38. WIDE LOCAL EXCISION
• The definitive surgical treatment
• The recommended width of the normal tissue around the
lesion has progressively decreased as a result of multiple large
clinical trials that have examined the impact of the surgical
margin on the local recurrence rate
• The thickness of the melanoma is a key factor in determining
the stage of the lesion and the recommended margin of
normal tissue to be resected.
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39. Study, author;
year
n
Median
follow-up
Melanoma
thickness
Margi
ns
Local recurrence,
(percent)
Overall survival,
percent
World Health
Organization
Cascinelli, N; 1998
612 12 yrs 0-1 mm 1 cm 3/186 (1.6) 87
1.1-2 mm 1 cm 5/119 (4.2)
0-1 mm 3 cm 1/173 (0.6) 85
1.1-2 mm 3 cm 2/134 (1.5)
Swedish
Cohn-Cedarmark, G;
2000
989 11 yrs 0.8-2 mm 2 cm 3/476 (0.6) 79
5 cm 5/513 (1) 76
French Cooperative
Group
Khayat, D; 2003
326 16 yrs <2.1 mm 2 cm 1/181 (0.05) 87
5 cm 4/185 (0.2) 86
Melanoma
Intergroup Trial
Karakoussis, CP;
1996
468 8 yrs 1-4 mm 2 cm (2.1) 80
4 cm (2.6) 84
British Trial
Thomas, JM; 2004
900 60 mos ≥2 mm 1 cm 15/453 (3.3) No significant
difference3 cm 13/457 (2.8)
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40. WIDE LOCAL EXCISION
• Thin melanomas
• Resect melanomas <1 mm thick (T1) with a 1 cm margin of normal
tissue
• For melanomas 1 to 2 mm thick (T2 lesions), use a 2 cm margin of
normal tissue if this is feasible without the need for a skin graft
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41. • Intermediate thickness melanomas
• Primary melanomas between 2 and 4 mm thick (T3), 2 cm excision
margin
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43. • In situ melanomas
• There are no data from randomized trials to define the optimal extent
of surgical resection.
• Retrospective data support the routine use of 0.5 cm margins
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44. LYMPH NODE METASTASIS
• 20 percent of clinically node-negative patients have
metastatic involvement
• 20 percent of those with clinically positive nodes are
pathologically negative
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46. THERAPEUTIC LYMPHADENECTOMY
• Therapeutic lymphadenectomy is the preferred treatment
for cytologically or pathologically proven regional lymph
node involvement
• Complete regional lymphadenectomy is necessary rather
than partial dissection or sampling
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47. ELECTIVE LYMPH NODE DISSECTION
• ELND for clinically node-negative patients is controversial
despite a number of trials evaluating this approach
• There may be subgroups of patients who benefit from
ELND, but consensus is lacking on this issue.
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48. SENTINEL LYMPH NODE BIOPSY
• If the sentinel lymph nodes are not involved, the entire
basin should be free of tumor
• Completion lymph node dissection is used for patients
with tumor involvement of the sentinel lymph node
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49. • Patient selection
• SLNB is indicated for tumors ≥1 mm thick.
• Tumors less than 1 mm in thickness have less than a 10 percent
likelihood of nodal metastases, and SLNB is not routinely indicated.
However, certain high-risk features (ulceration, a mitotic rate ≥1 per
mm2) are associated with a higher rate of lymph node metastasis,
thereby justifying the use of SLNB
• Tumors >4 mm thick have a 65 to 70 percent risk of distant metastasis.
However, SLNB may still provide important prognostic information.
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50. SURVEILLANCE AFTER TREATMENT
• The primary objective of follow-up in patients with
melanoma is to identify potentially curable locoregional
recurrences and second primary cancers.
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51. • A routine physical examination, including a full skin
assessment and palpation of the regional lymph nodes,
which should be repeated at least yearly
• The frequency of such evaluation should be increased in
patients at high risk of recurrence
• Imaging studies should be done if symptoms are present;
the value of routine imaging is uncertain
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